The invention concerns an acoustic diffuser, ovaloid, ellipsoid or spheroid in shape, made in a monocoque so as to eliminate the acoustic reflections, refractions and vibrations which damage the quality of the sound.
The invention also concerns the method to produce said acoustic diffuser.
The state of the art includes acoustic diffusers having containers composed of at least two semi-coques made of plastic material, plywood or composite materials, attached together and with a substantially box-like shape.
Such diffusers usually comprise at least a loudspeaker able to broadcast the sound, possibly associated with a printed circuit able to support an electric-acoustic filter, for example of the crossover type, an electric connector, for example of the jack type.
Acoustic diffusers made in this way create vibrations, reverberations, or other distortions inside, which affect the quality of the sound.
The present Applicant has devised and embodied this invention to overcome this shortcoming of the state of the art, and to obtain further advantages.
The invention is set forth and characterized essentially in the main claims, while the dependent claims describe other innovative characteristics of the invention.
One purpose of the invention is to achieve an acoustic diffuser which will prevent the formation of echoes, reverberations or vibrations inside it, and of refractions in the emission of sound.
Another purpose of the invention is to achieve an acoustic diffuser which is attached so as to limit the diffusion or transmission of contact vibrations, and which can be installed easily, and positioned at different heights, and directed at an angle in space.
Another purpose is to perfect a method which will allow to make a monocoque acoustic diffuser in a simple and efficient manner.
In accordance with these purposes the acoustic diffuser according to the invention comprises a containing element formed by a monocoque and at least a loudspeaker.
The monocoque is made from a compound of solid mineral aggregates, for example silicon, basalt and quartz, and a cohesion material, such as for example an epoxy resin, so as to limit the vibrations and to ensure a high structural density in order to optimize the frequency of resonance. The monocoque is substantially rounded in shape, such as for example ovaloid, ellipsoid or spheroid, in order to eliminate acoustic reflections and the formation of reverberations inside it.
The acoustic diffuser comprises, in one embodiment, an outer covering shell composed by an abradable resin, and an inner shell formed by plastic material. The two shells follow the outer, respectively inner, profile of the monocoque and provide the through holes able to house the loudspeaker and/or any other electric and electronic components such as, for example, connectors, pre-printed circuits, or for acoustic devices such as for example vents to allow the air, put under pressure by the movement of the loudspeaker, to exit from the containing element.
The acoustic diffuser also comprises support means which allow it to be fixed from above to at least one surface; in this case, they are formed by a steel cable which is inserted into a cavity of the containing element and a shock absorber element inserted between one end of the steel cable and the containing element, so as not to transmit the possible vibrations of the containing element to the surface.
The acoustic diffuser as described heretofore is made according to the following method.
The containing element is formed by inserting solid mineral aggregates, for example with a high level of hardness with a granulometry varying from about 1 mm to about 5 mm, inside a mold and the subsequent casting, or insertion under pressure, of a cohesion material into the same mold, so that the resulting containing element consists of a monocoque.
The mold has a substantially rounded inner surface, such as for example ellipsoid, ovaloid or similar, and is formed by two substantially symmetrical half-molds.
An inner shell is positioned inside the mold, so as to define an interspace inside which the granules and the cohesion material are cast.
In one embodiment, an outer shell is shaped on the inner surface of the mold, so as to form, together with the inner shell, an interspace inside which the granules of hard mineral, and subsequently the cohesion material, will be inserted.
Once the cohesion material has solidified, the two half-molds are removed and the surface finishing of the monocoque, or of the outer shell, is done, the loudspeaker is assembled, and any other possible electric and electronic components or acoustic devices provided.